As we’re sure you’ve heard, Governor Brown has now declared California in a state of emergency drought. However for those of us around the state, the cloudless sunny skies and wilting trees are already clear proof.
Water is essential to life, and trees are no exception. Trees need water for photosynthesis (food production) and to replace water lost to evaporation. Since urban trees are dependent on humans, if we want to continue with benefiting from the valuable gifts of trees such as shade, fruit, increased property values etc., we need to take good care of our trees.
We’ve put together the following water wise guidelines to help you preserve your trees, the most valuable assets in our landscapes.
- Consider tree age, location and timing in prioritizing watering:
- New trees have less established roots and thus need easier access to water.
- Mature trees near driveways and house foundations, or in areas with utility lines might also be at a higher risk due to root loss and as these trees experience more heat than those in the middle of a landscaped area.
- Exposure to sunlight and wind. Water loss is greater where trees are exposed to hot afternoon sun and strong or constant wind. It is less where trees are shaded and sheltered by buildings or mountains.
- For deciduous trees, the most critical time for water is during bud-break in spring and bud formation in late summer.
- Provide the right amount of water. Arborists recommend watering young trees twice per week and mature trees once per week. Mature trees require the equivalent of 1 to 1.5 inches of rain per week during the growing season.
- Watering early in the morning or after the sun has set. At nighttime trees replace the water they have lost during the day.
- Deep watering is essential! Do not give small amounts of water – this does more harm than good. This encourages shallow roots that dry quickly.
- Use recycled water or gray water from your home. Place a bucket in the shower to collect water while the shower water heats up and use this for your tree. Other sources of usable water include dehumidifier, air conditioning condensation etc.
- Watering method. During droughts, water directly with a hose or 5-gallon bucket, or gator bag filled with recycle water rather than a sprinkler.
- Water the dripzone. Water only the “drip zone,” those areas directly beneath the foliage and shaded by the tree. Avoid directly irrigating the trunk of the tree, as the increased moisture can favor root rot disease.
- Don’t waste precious water. Water so that it soaks into the ground rather than running off.
Download the attached infographic and share with your neighbor. Tune in next week for more tips to help your trees survive the drought.